Image sensors

ABSTRACT

An image sensor may include a substrate which includes a plurality of block regions. Each block region may include a separate plurality of pixel regions. Each pixel region may include a separate photoelectric element of a plurality of photoelectric elements in the substrate and a separate micro lens of a plurality of micro lenses on the substrate. Each micro lens of the plurality of micro lenses may be laterally offset from a vertical centerline of the pixel region towards a center of the block region. Each block region of the plurality of block regions may include a common shifted shape of the plurality of micro lenses of the block region.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/014,088, filed on Jun. 21, 2018, which claims priority, under 35U.S.C. § 119, from Korean Patent Application No. 10-2018-0003164 filedon Jan. 10, 2018 in the Korean Intellectual Property Office, and all thebenefits accruing therefrom under 35 U.S.C. 119, the contents of whichin its entirety are herein incorporated by reference.

BACKGROUND 1. Field of the Invention

The present inventive concepts relate to an image sensor.

2. Description of the Related Art

An image sensor of a semiconductor device is an element that converts anoptical image into an electrical signal. Image sensors may be classifiedinto a CCD (charge coupled device) type and a CMOS (complementary metaloxide semiconductor) type. The CMOS type image sensor is abbreviated asa CIS (CMOS image sensor). The CIS includes a plurality oftwo-dimensionally arranged pixels. Each of the pixels includes aphotodiode. The photodiode serves to convert the incident beam into anelectrical signal.

Recently, in accordance with the development of the computer industryand the communication industry, demand for image sensors with improvedperformance has been increased in various fields such as a digitalcamera, a video camera, a PCS (personal communication system), a gamemachine, a security camera, a medical micro camera and robot. Inaddition, as the semiconductor devices are highly integrated, imagesensors are also highly integrated.

SUMMARY

Some aspects of the present inventive concepts provide image sensorswhich are configured to provide an image with improved resolution andvisibility based on dividing the shift of the micro lenses of said imagesensors as one or more block units.

The aspects of the present inventive concepts are not limited to thosementioned above and another aspect which is not mentioned can be clearlyunderstood by those skilled in the art from the description below.

According some example embodiments, an image sensor may include asubstrate which includes a plurality of block regions. Each block regionof the plurality of block regions may include a separate plurality ofpixel regions. Each pixel region of each block region may include aseparate photoelectric element of a plurality of photoelectric elementsin the substrate and a separate micro lens of a plurality of microlenses on the substrate, wherein each micro lens of the plurality ofmicro lenses is laterally offset from a vertical centerline of the pixelregion towards a center of the block region. Each block region of theplurality of block regions may include a common shifted shape of theplurality of micro lenses of the block region.

According to some example embodiments, an image sensor may include asubstrate, the substrate including a first block region and a secondblock region, the first block region including a first pixel region anda second pixel region, and the second block region including a thirdpixel region and a fourth pixel region. The first through fourth pixelregions may include first to fourth photoelectric elements in separate,respective pixel regions of the first to fourth pixel regions and firstto fourth micro lenses on separate, respective pixel regions of thefirst to fourth pixel regions. A distance between a vertical centerlineof the first pixel region and a center of the first block region may bea first distance, a distance between a vertical centerline of the secondpixel region and the center of the first block region may be a seconddistance, a distance between a vertical centerline of the third pixelregion and a center of the second block region may be the firstdistance, and a distance between a vertical centerline of the fourthpixel region and the center of the second block region may be the seconddistance. The first micro lens may be laterally offset from the verticalcenterline of the first pixel region by a first interval towards thecenter of the first block region, the second micro lens may be laterallyoffset from the vertical centerline of the second pixel region by asecond interval towards the center of the first block region by a secondinternal, the third micro lens may be laterally offset from the verticalcenterline of the third pixel region by the first interval towards thecenter of the second block region, and the fourth micro lens may belaterally offset from the vertical centerline of the fourth pixel regionby the second interval towards the center of the second block region.

According to some example embodiments, an image sensor may include asubstrate, the substrate including a first block region, a second blockregion, and a third block region, the first through third block regionsincluding separate, respective pluralities of pixel regions. The imagesensor may include a first boundary separation film in the substrate,the first boundary separation film defining the first and second blockregions such that the first boundary separation film is divided betweenthe first and second block regions. The image sensor may include asecond boundary separation film in the substrate, the second boundaryseparation film defining the second and third block regions such thatthe second boundary separation film is divided between the second andthird block regions. The image sensor may include a plurality of microlenses on the substrate and on separate, respective pixel regions of thepluralities of pixel regions of the first through third block regions.Intervals between micro lenses of the pluralities of micro lenses may benot constant. The plurality of micro lenses located in the first blockregion and the plurality of micro lenses located in the second blockregion may collectively include a symmetrical pattern of micro lenseswith each other on a basis of the first boundary separation film. Theplurality of micro lenses located in the second block region and theplurality of micro lenses located in the third block region maycollectively include a symmetrical pattern of micro lenses with eachother on a basis of the second boundary separation film.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present inventiveconcepts will become more apparent by describing in detail exampleembodiments thereof with reference to the attached drawings, in which:

FIG. 1 is a block diagram illustrating an image sensor according to someexample embodiments of the present inventive concepts;

FIG. 2 is a block diagram of the image sensor for explaining the controlcircuit of FIG. 1 in detail;

FIG. 3 is an equivalent circuit diagram of a pixel array of FIG. 2;

FIG. 4 is a plan conceptual diagram for explaining the arrangement of ablock region and a pixel region of the pixel array of FIG. 2;

FIG. 5 is a conceptual diagram for explaining a block region of an imagesensor according to some example embodiments of the present inventiveconcepts;

FIG. 6 is a plan view for explaining shift of micro lenses of an imagesensor according to some example embodiments of the present inventiveconcepts;

FIG. 7 is a cross-sectional view taken along a line VII-VII′ of FIG. 6;

FIG. 8 is a plan view for explaining shift of micro lenses of the imagesensor according to some example embodiments of the present inventiveconcepts;

FIG. 9 is a plan view for explaining an image sensor including the blockregion of FIG. 8;

FIG. 10 is a cross-sectional view taken along a line X-X′ of FIG. 9;

FIG. 11 is a cross-sectional view for explaining the image sensoraccording to some example embodiments of the present inventive concepts;

FIG. 12 is a conceptual perspective view for explaining a fingerprintsensing system including the image sensor of FIG. 11;

FIG. 13 is an exploded perspective view for explaining the fingerprintsensing system including the image sensor of FIG. 11;

FIG. 14 is a block diagram for explaining the image sensor according tosome example embodiments of the present inventive concepts;

FIG. 15 is a conceptual diagram for explaining the image sensoraccording to some example embodiments of the present inventive concepts;and

FIG. 16 is a conceptual diagram for explaining a binning mode of animage sensor according to some example embodiments of the presentinventive concepts.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, an image sensor according to some example embodiments ofthe present inventive concepts will be described with reference to FIGS.1 to 10.

FIG. 1 is a block diagram illustrating the image sensor according tosome example embodiments of the present inventive concepts.

Referring to FIG. 1, a first image sensor 1220 may include a controlcircuit 2000 and a pixel array 1000.

The pixel array 1000 includes a plurality of two-dimensionally arrangedunit pixels. The plurality of unit pixels serves to convert an opticalimage into an electrical output signal.

The control circuit 2000 is connected to the pixel array 1000 to applyinput signals to the pixel array 1000, and may receive the transmissionof output signals from the pixel array 1000. For example, the controlcircuit 2000 may receive electrical signals generated by a plurality ofphotoelectric elements 110 included in the pixel array 1000, asdescribed further below. The control circuit 2000 may control theoverall operation of the pixel array 1000.

FIG. 2 is a block diagram of the image sensor for explaining the controlcircuit of FIG. 1 in detail.

Referring to FIG. 2, the control circuit 2000 includes a timinggenerator 2100, a row decoder 2200, a row driver 2300, a correlateddouble sampler (CDS) 2500, an analog-to-digital converter (ADC) 2600, alatch 2700, a column decoder 2800, and the like.

The pixel array 1000 is driven by receiving a plurality of drivingsignals, such as a row selection signal, a reset signal, and a chargetransmission signal, from the row driver 2300. In some exampleembodiments, the converted electrical output signal is provided to thecorrelated double sampler 2500 via a vertical signal line.

The timing generator 2100 provides a timing signal and a control signalto the row decoder 2200 and the column decoder 2800.

The row driver 2300 provides a plurality of driving signals for drivingthe plurality of unit pixels to the pixel array 1000 in accordance withthe results decoded by the row decoder 2200. Generally, when the unitpixels are arranged in the form of a matrix, the driving signals areprovided for each row.

The correlated double sampler 2500 receives the output signals formed onthe pixel array 1000 through the vertical signal lines to hold andsamples the output signals. That is, a specific noise level and a signallevel due to the output signal are doubly sampled to output a differencelevel corresponding to a difference between the noise level and thesignal level.

The analog-to-digital converter 2600 converts the analog signalcorresponding to the difference level into a digital signal and outputsthe converted signal.

The latch 2700 latches the digital signal, and the latched signal issequentially output to the video signal processing unit in accordancewith the decoding result in the column decoder 2800.

FIG. 3 is an equivalent circuit diagram of the pixel array of FIG. 2.

Referring to FIG. 3, the pixels P are arranged in a matrix form to forma pixel array 1000. Each pixel P includes a phototransistor 11, afloating diffusion region 13, a charge transfer transistor 15, a drivetransistor 17, a reset transistor 18, and a selection transistor 19. Thefunctions thereof will be described using an i row pixels (P(i, j), P(i,j+1), P(i, j+2), P(i, j+3), . . . ) as an example.

The photoelectric transistor 11 absorbs incident beam and accumulatescharges corresponding to the beam quantity. A photodiode, aphototransistor, a photogate, a pinned photodiode or a combinationthereof can be applied to the photoelectric transistor 11, and aphotodiode is illustrated in the drawing.

Each photoelectric transistor 11 is coupled with each charge transfertransistor 15 which transmits the accumulated charge to the floatingdiffusion region 13. Since the floating diffusion region 13 is a regionwhich converts charge to voltage and has a parasitic capacitance,charges are stored accumulatively.

The drive transistor 17 exemplified as a source follower amplifieramplifies the change in the electric potential of the floating diffusionregion 13 which receives the transmission of the charge accumulated ineach photoelectric transistor 11, and supplies it to an output line(Vout).

The reset transistor 18 periodically resets the floating diffusionregion 13. The reset transistor 18 may include a single MOS transistorwhich is driven by a bias provided by a reset line 18 i which applies aparticular (or, alternatively, predetermined) bias (i.e., a resetsignal). When the reset transistor 18 is turned on by the bias providedby the reset line 18 i, the particular (or, alternatively,predetermined) electric potential provided to the drain of the resettransistor 18, for example, the power supply voltage (VDD) istransferred to the floating diffusion region 13.

The selection transistor 19 serves to select the pixels P to be read inrow units. The selection transistor 19 may include a single MOStransistor which is driven by the bias (i.e., the row selection signal)provided by the row select line (SELi). When the selection transistor 19is turned on by the bias provided by the row selection line (SELi), theparticular (or, alternatively, predetermined) electric potentialprovided to the drain of the selection transistor 19, for example, thepower supply voltage (VDD) is transferred to the drain region of thedrive transistor 17.

A transfer line 15 i which applies the bias to the charge transfertransistor 15, a reset line 18 i which applies the bias to the resettransistor 18, and a row selection line (SEL(i)) which applies the biasto the selection transistor 19 may be arranged to extend substantiallyparallel to each other in the row direction.

FIG. 4 is a schematic plan view for explaining the arrangement of theblock region and the pixel region of the pixel array of FIG. 2.

Referring to FIG. 4, the pixel array 1000 may include a plurality ofpixel regions (P1 to P7, P101 to P107, P201 to P207, P301 to P307, P401to P407, P501 to P507, and P601 to P607).

The plurality of pixel regions (P1 to P7, P101 to P107, P201 to P207,P301 to P307, P401 to P407, P501 to P507, and P601 to P607) may bedefined as a plurality of rows and a plurality of columns. In FIG. 4,only 49 pixel regions of 7 rows and 7 columns are illustrated, but thisillustrates only a partial pixel region for the sake of convenience, andthe inventive concepts are not limited thereto. That is, the number ofpixel regions may be variously applied.

The row signal lines (R1 to R7) may be connected to each row of theplurality of pixel regions (P1 to P7, P101 to P107, P201 to P207, P301to P307, P401 to P407, P501 to P507, and P601 to P607). Each of the rowsignal lines (R1 to R7) may be SEL(i) of FIG. 3. That is, a signal canbe applied to the pixel regions of the entire row via one row signalline (R1 to R7).

The column signal lines (C1 to C7) may be connected to each column ofthe plurality of pixel regions (P1 to P7, P101 to P107, P201 to P207,P301 to P307, P401 to P407, P501 to P507, P601 to P607). Each columnsignal line (C1 to C7) may be Vout of FIG. 3. That is, the signal of thepixel region of the entire columns can be output via one column signalline (C1 to C7).

Each of the plurality of pixel regions (P1 to P7, P101 to P107, P201 toP207, P301 to P307, P401 to P407, P501 to P507, and P601 to P607) can beclassified into a plurality of block regions (B1 to B9). That is, aplurality of pixel regions can be included in one block region. Forexample, the first block region B1 may include a plurality of pixelregions (P1 to P3, P101 to P103, and P201 to P203).

The plurality of block regions (B1 to B9) may include block regionshaving the same (“a common”) size and shape. For example, the firstblock region B1 and the second block region B2 may have the same squareshape and the same size. Each block region may include the same numberof pixel regions.

In FIG. 4, since one block region can be include nine pixel regions andis a square, the pixel region may have three rows and three columns.However, the present inventive concepts is not limited to theseexamples. The number of pixel regions belonging to one block region maybe variously changed.

FIG. 5 is a conceptual diagram for explaining a block region of anotherimage sensor according to some example embodiments of the presentinventive concepts.

Referring to FIG. 5, the first block region B1 may include a total of 12pixel regions (P1 to P4, P101 to P104, and P201 to P204). At least oneblock region (e.g., B1) may have a square shape. The first block regionB1 may be a rectangle rather than a square. Restated, at least one blockregion (e.g., B1) may have a rectangle shape. In this way, the shape ofthe block region of the first image sensor 1220 according to someexample embodiments of the present inventive concepts may vary dependingon the particular purpose and need.

FIG. 6 is a plan view illustrating shift of micro lenses of the imagesensor according to some example embodiments of the present inventiveconcepts. Since other blocks also have the same structure as the firstblock region B1, only the first block region B1 will be explained inFIG. 6 for the sake of convenience.

Referring to FIG. 6, each of the pixel regions (P1 to P3, P101 to P103,and P201 to P203) may include a micro lens 220. The micro lenses 220 maybe disposed one by one on the respective pixel regions (P1 to P3, P101to P103, and P201 to P203).

The micro lenses of the respective pixel regions (P1 to P3, P101 toP103, and P201 to P203) are not disposed at the center of each pixelregion (P1 to P3, P101 to P103, and P201 to P203) and may be shifted.Specifically, the micro lens 220 may be disposed to be biased in thedirection of the center BC1 of the first block region B1.

At this time, the shifted degree of the micro lens 220, that is, thebiased degree may vary depending on the distance between the center ofeach pixel region (P1 to P3, P101 to P103, and P201 to P203) and thecenter BC1 of the first block region B1.

Specifically, since the P102 pixel region has the same center as thecenter BC1 of the first block region B1, it may not be shifted from thecenter of the P102 pixel.

Since the P2, P101, P103, and P202 pixel regions are adjacent to theP102 pixel region to share the side surface, the distance between thecenter BC1 of the first block region B1 and the center of each pixelregion may be the same as a first distance D1.

The micro lenses 220 of the P2, P101, P103, and P202 pixel regions maybe shifted in the direction of the P102 pixel region, that is, in thedirection of the center BC1 of the first block region B1 from a verticalcenterline of a pixel region (e.g., vertical centerline PC2 of pixelregion P2) by a first interval S1.

Unlike this, since the P1, P3, P201 and P203 pixel regions are adjacentto the pixel region of P102 in a diagonal direction, the distancebetween the center BC1 of the first block region B1 and the center ofeach pixel region may be the same as a second distance D2. At this time,the second distance D2 may naturally be larger than the first distanceD1.

The micro lenses 220 of the P1, P3, P201 and P203 pixel regions may beshifted by the second interval S2 in the direction of the P102 pixelregion, that is, in the direction of the center BC1 of the first blockregion B1. At this time, the second interval S2 may be larger than thefirst interval S1.

That is, the interval at which the micro lens 220 of each pixel regionof the first block region B1 is shifted may be determined in accordancewith the distance between the center of the first block region B1 andthe center of each pixel region. Specifically, as the distance betweenthe center of the first block region B1 and the center of each pixelregion is large, the interval at which the micro lenses 220 of eachpixel region are shifted may increase.

FIG. 7 is a cross-sectional view taken along a line VII-VII′ of FIG. 6.

The first image sensor 1220 according to some example embodiments of thepresent inventive concepts includes a substrate 100, a photoelectricelement 110, a boundary separation film 130, a fixed charge layer 160, areflection prevention film 170, a lower planarization film 180, a colorfilter 200, a side surface reflection prevention film 190, an upperplanarization film 210, a micro lens 220, a protective film 230, and aninsulation structure 300. In the case of another pixel region, sinceother parts except the position of the micro lens 220 are the same asthose of the P102 pixel region, only the P102 pixel region will bedescribed for convenience.

The substrate 100 includes a first side 100 a and a second side 100 bopposite to each other. The first side 100 a of the substrate 100 may bea front side of the substrate 100, and the second side 100 b of thesubstrate may be a back side of the substrate. However, the presentinventive concepts is not limited thereto.

As shown in FIG. 7, a pixel region (e.g., P102 pixel region) includes avertical centerline (e.g., PC102) that extends orthogonally to the sides100 a and 100 b of the substrate 100. In some example embodiments, forexample where the pixel region (e.g., P102 pixel region) is located inthe center of a block region (e.g., block region B1), the verticalcenterline of the pixel region (e.g., PC103) and the center of the blockregion (e.g., BC1) may be identical.

As shown in at least FIG. 7, the color filter 200, which may also bereferred to herein as the “color filter layer,” may be between thesubstrate 100 and the micro lens 220. The color filter 200 may have anyone of at least a red color, a blue color, or a green color. Restated,the color filter 200 may be configured to selectively filter anyparticular one of red light, blue light, or green light.

For example, the substrate 100 may use a P type or N type bulksubstrate, or may be used by growing the P type or N type epitaxiallayer on a P type bulk substrate, or by growing the P type or N typeepitaxial layer on a N type bulk substrate. In addition to asemiconductor substrate, a substrate such as an organic or plasticsubstrate can also be used as the substrate 100.

The P102 pixel region may be formed in the substrate 100. The P102 pixelregion may be a region in which incident beam incident through the microlens 220 from outside is detected, respectively. The P102 pixel regionmay be defined to be separated from other pixel regions by the boundaryseparation film 130 which will be described later.

For example, the photoelectric element 110, for example, a photodiode isformed in each of the substrate 100 of the P102 pixel region. Thephotoelectric element 110 may be formed close to the first side 100 a ofthe substrate 100, but is not limited thereto.

The photoelectric element 110 may be the photoelectric transistor 11 ofFIG. 3 described above, that is, a photodiode, a phototransistor, aphotogate, a pinned photodiode or a combination thereof. Thephotoelectric element 110 may be configured to generate an electricalsignal, and the electrical signal may be communicated from pixel array1000 (in which block region B1 may be located) to control circuit 2000.

The boundary separation film 130 may be formed in the substrate 100. Theboundary separation film 130 may define the P102 pixel region within thesubstrate 100. The boundary separation film 130 may be formed at theedges of each of the P102 pixel regions. By the boundary separation film130, the P102 pixel region may be defined as a closed space. The planarcross-sectional shape of the boundary separation film 130 may be aclosed curve in the form of a loop.

The boundary separation film 130 may be formed in the boundaryseparation trench 120. The boundary separation trench 120 may be formedby being etched in the depth direction in the substrate 100. Theboundary separation trench 120 may be formed on the second side 100 b ofthe substrate 100 and extend in the direction of the first side 100 a.The boundary separation trench 120 may not reach the second side 100 bof the substrate 100.

At this time, the depth of the boundary separation trench 120 may besmaller than the depth at which the photoelectric element 110 islocated. This is for the purpose of preventing the photoelectric elementfrom being damaged by the formation of the boundary separation trench120. However, the inventive concepts are not limited thereto.

In the image sensor according to some example embodiments of the presentinventive concepts, when the boundary separation trench 120 is formed sothat the horizontal distance from the photoelectric element 110 issufficiently for away, the depth of the boundary separation trench 120may be deeper than the depth at which the photoelectric element 110 islocated.

The side surface of the boundary separation trench 120 may have atapered shape as shown in FIG. 7. Specifically, the width of theboundary separation trench 120 may become narrower toward a downwarddirection, and may become wider toward an upward direction. However, theinventive concepts are not limited thereto.

As shown in the drawing, the boundary separation film 130 may be filledwith a fixed charge layer 160 to be described later, and a reflectionprevention film 170 formed on the fixed charge layer 160.

In some example embodiments, the boundary separation film 130 may befilled with one substance. In such a case, the fixed charge layer 160and the reflection prevention film 170 may be formed on the boundaryseparation film 130. At this time, the boundary separation film 130 mayinclude at least one of silicon oxide, silicon nitride, siliconoxynitride and a low dielectric constant substance having a lowerdielectric constant than silicon oxide. The low dielectric constantsubstance may include, for example, but is not limited to, FOX (FlowableOxide), TOSZ (Tonen SilaZene), USG (Undoped Silica Glass), BSG(Borosilica Glass), PSG (PhosphoSilica Glass), BPSG (BoroPhosphoSilicaGlass), PETEOS (Plasma Enhanced Tetra Ethyl Ortho Silicate), FSG(Fluoride Silicate Glass), CDO (Carbon Doped Silicon Oxide), Xerogel,Aerogel, Amorphous Fluorinated Carbon, OSG (Organo Silicate Glass),Parylene, BCB (bis-benzocyclobutenes), SiLK, polyimide, porous polymericsubstance, or a combination thereof.

The upper surface of the boundary separation film 130 and the uppersurface of the substrate 100 may be the same plane. However, the presentinventive concepts is not limited to these examples.

The fixed charge layer 160 may be formed on the second side 100 b of thesubstrate 100 and the surface (side surface and bottom surface) of theboundary separation trench 120. The fixed charge layer 160 may be formedon the whole surface or a partial surface of the second side 100 b ofthe substrate 100.

The fixed charge layer 160 may be formed into a P+ type in the casewhere the photoelectric element 110 formed in the pixel region, forexample, the photodiode (11 of FIG. 3) is an N type. That is, the fixedcharge layer 160 serves to reduce the dark current by reducing EHP(Electron-Hole Pair) thermally generated o the second side 100 b of thesubstrate 100. In some cases, the fixed charge layer 160 may be omitted.

For example, the fixed charge layer 160 includes, for example, a metaloxide film or a metal nitride film, and as the metal, hafnium (Hf),aluminum (Al), zirconium (Zr), tantalum (Ta), and titanium (Ti) may beused. Further, the fixed charge layer 160 may include at least one ofLa, Pr, Ce, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, Lu and Y.Furthermore, the fixed charge layer 160 may be formed of a hafniumoxynitride film or an aluminum oxynitride film.

Although the fixed charge layer 160 is illustrated as a single layer inthe drawings, the fixed charge layer 160 may be a laminated structure inwhich two or more layers formed of the same or different substances arecombined.

The reflection prevention film 170 may be formed on the fixed chargelayer 160. The reflection prevention film 170 may completely fill theboundary separation trench 120. The reflection prevention film 170 mayserve to prevent reflection of beam which is incident from the outside.The reflection prevention film 170 may include substances havingdifferent refractive index from the fixed charge layer 160. For example,the reflection prevention film 170 may be formed of an insulating film,such as a silicon oxide film, a silicon nitride film, a siliconoxynitride film, a resin, a combination thereof, or a laminate thereof.

The configuration of the double layer of the fixed charge layer 160 andthe reflection prevention film 170 may have a reflection preventionfunction by the different refraction coefficients mentioned above.Therefore, reflection of beam incident on the second side 100 b of thesubstrate 100 may be prevented.

The substance and the thickness of the reflection prevention film 170may change, depending on the wavelength of the beam used in the photoprocess. For example, a silicon oxide film having a thickness of about50 to 200 Å and a silicon nitride film having a thickness of about 300to 500 Å may be stacked and used as the reflection prevention film 170.However, the inventive concepts are not limited thereto.

The lower planarization film 180 may be formed on the reflectionprevention film 170, the fixed charge layer 160, and the substrate 100.The lower planarization film 180 may include, for example, at least oneof a silicon oxide film-based substance, a silicon nitride film-basedsubstance, a resin, or a combination thereof.

The lower planarization film 180 may be used as a buffer film forpreventing the substrate 100 from being damaged in a patterning processfor forming a pad (not shown) in the non-pixel region.

The lower planarization film 180 may include at least one of a siliconoxide film-based substance, a silicon nitride film-based substance, aresin, or a combination thereof. As the lower planarization film 180,for example, a silicon oxide film having a thickness of about 3000 to8000 Å may be used. However, the inventive concepts are not limitedthereto.

The color filter 200 may be formed on the lower planarization film 180.The color filter 200 may filter the remaining wavelength bands exceptthe partial wavelength regions of the incident beam. For example, in thecase of a blue color filter, the color filter 200 may filter theremaining wavelength bands except the blue beam, and in the case of ared color filter, the color filter 200 may filter the remainingwavelength bands except the red beam. Further, in the case of a greencolor filter, the color filter 200 may filter the remaining wavelengthbands except the green beam.

As a result, the beam having passed through the color filter 200 may bebeam having a specific color. The beam having passed through the colorfilter 200 may reach the photoelectric element 110 through the lowerstructures. The photoelectric element 110 may generate an electriccurrent by the incident beam of a specific color.

The side surface reflection prevention film 190 may be formed on thelower planarization film 180. The side surface reflection preventionfilm 190 may cover a part of the lower planarization film 180. The sidesurface reflection prevention film 190 may overlap the boundaryseparation film 130 in a vertical direction. That is, the side surfacereflection prevention film 190 may be disposed at the edge of the P102pixel region.

The side surface reflection prevention film 190 may be disposed on theside surface of the color filter 200. Specifically, the color filter 200may cover the side surface and the upper surface of the side surfacereflection prevention film 190. That is, the height of the upper surfaceof the side surface reflection prevention film 190 may be lower than theheight of the upper surface of the color filter 200.

The side surface reflection prevention film 190 may prevent incidentbeam passing through the color filter 200 from being reflected orscattered to the side surface. That is, the side surface reflectionprevention film 190 may prevent photons reflected or scattered at theinterface between the color filter 200 and the lower planarization film180 from moving to other sensing regions. Since the side surfacereflection prevention film 190 acts at the interface as described above,it may cover only a part of the side surface of the color filter 200.

The side surface reflection prevention film 190 may include a metal. Theside surface reflection prevention film 190 may include, for example, atleast one of tungsten (W), aluminum (Al), and copper (Cu).

The upper planarization film 210 may be formed flat on the color filter200. The upper planarization film 210 may include at least one of, forexample, a silicon oxide film-based substance, a silicon nitridefilm-based substance, a resin, or a combination thereof. Although theupper planarization film 210 is illustrated as a single film, this isonly for the convenience of description, and the inventive concepts arenot limited thereto.

Although FIG. 7 illustrates a configuration in which the upperplanarization film 210 and the lower planarization film 180 are formedon the upper side and the lower side of the color filter 200,respectively, as an example, the inventive concepts are not limitedthereto. For example, a planarization film may be formed only on thelower side of the color filter 200, or a planarization film may beformed only on the upper side of the color filter 200. In some exampleembodiments, no planarization film may present on both the upper sideand the lower side of the color filter 200.

The micro lens 220 may be formed on the upper planarization film 210.The micro lens 220 may have an upward convex shape as shown. The convexshape of the micro lens 220 serves to cause incident beam to concentratein the P102 pixel region.

The micro lens 220 may be made of an organic substance such as PR (PhotoResist). However, the inventive concepts are not limited thereto, andthe micro lens 220 may be formed using an inorganic substance. Formationof the micro lens 220 with the organic substance may be formation of themicro lens 220, for example, by forming an organic substance pattern onthe upper planarization film 210 and by performing a thermal process.The organic substance pattern mat change to the form of micro lenses 220by the thermal process.

The protective film 230 may be formed with a constant thickness alongthe surface of the micro lens 220. The protective film 230 may be amineral oxide film. For example, a silicon oxide film (SiO₂), a titaniumoxide film (TiO₂), a zirconium oxide film (ZrO₂), a hafnium oxide film(HfO₂), a laminated film thereof and a combination thereof may be used.In particular, LTO (Low Temperature Oxide) which is a type of siliconoxide film may be used for the protective film 230. The reason for usingLTO in this way is that, since LTO is manufactured at a low temperature(about 100° C. to 200° C.), damage to the lower film can be reduced.Furthermore, since LTO is amorphous, the surface is smooth and thereflection/refraction/scattering or the like of incident beam can besuppressed to the minimum.

Since the micro lens 220 is made of an organic substance, it may bevulnerable to external shock. Therefore, the protective film 230 servesto protect the micro lens 220 from external impact. Furthermore, theremay be some space between adjacent micro lenses, but the protective film230 serves to fill such a space.

If the space between the adjacent micro lenses 220 is filled, thecondensing ability of incident beam can be improved. The reason is thatit is possible to reduce the reflection/refraction/scattering ofincident beam reaching the space between the adjacent micro lenses 220.

The insulating structure 300 may be formed on the first side 100 a ofthe substrate 100. That is, the insulation structure 300 may be formedon the front side of the substrate 100. The insulating structure 300 mayinclude an insulating layer 320, a gate structure 310, and a wiringstructure 330.

The insulating layer 320 may include at least one of, for example, asilicon oxide film, a silicon nitride film, a silicon oxynitride film, alow dielectric constant substance, and combinations thereof. Theinsulating layer 320 may cover and surround the gate structure 310 andthe wiring structure 330 to be described later. That is, the insulatinglayer 320 may be responsible for insulation between the gate structure310 and the wiring structure 330.

The gate structure 310 may be disposed on the first side 100 a of thesubstrate 100. The gate structure 310 may be, for example, the gate ofthe charge transfer transistor 15, the gate of the reset transistor 18,the gate of the selection transistor 19, the gate of the drivetransistor or the like.

Referring to FIGS. 6 and 7 again, the photoelectric element 110 and themicro lens 220 of the P102 pixel region may be arranged at the centerBC1 of the first block region B1. Since the P102 pixel region is a pixelregion located at the center of the first block region B1, the microlens 220 and the photoelectric element 110 are arranged. However, sinceother pixel regions are not located at the center of the first blockregion B1, the micro lens 220 may be shifted in the direction of thecenter BC1 of the first block region B1.

FIG. 8 is a plan view illustrating the shift of micro lens of the imagesensor according to some example embodiments of the present inventiveconcepts.

Referring to FIG. 8, the first block region B1 of the first image sensor1220 according to some example embodiments of the present inventiveconcepts may include a total of 25 pixel regions (P1 to P5, P101 toP105, P201 to P205, P301 to P305, and P401 to P405).

Each of the pixel regions (P1 to P5, P101 to P105, P201 to P205, P301 toP305, and P401 to P405) may include a micro lens 220. The micro lenses220 may be arranged one by one in each of the pixel regions (P1 to P5,P101 to P105, P201 to P205, P301 to P305, and P401 to P405). Restated,each pixel region of the block region B1 may include a separate microlens 220 of a plurality of micro lenses 220 on the substrate 100.

The micro lenses of the respective pixel regions (P1 to P5, P101 toP105, P201 to P205, P301 to P305, and P401 to P405) may be shiftedwithout being located at the center of the respective pixel regions (P1to P5, P101 to P105, P201 to P205, P301 to P305, and P 401 to P405).Specifically, the micro lens 220 may be disposed to be biased in thedirection of the center BC1 of the first block region B1. Restated, eachmicro lens 220 of the plurality of micro lenses 220 in the block regionB1 may be laterally offset (e.g., by interval S3 in pixel region P3)from a vertical centerline (e.g., PC3) of the pixel region in which themicro lens 220 is included (e.g., P3) towards a center BC1 of the blockregion B1.

At this time, the shifted degree of the micro lens 220, that is, thebiased degree may vary depending on the distance between the center ofeach pixel region (P1 to P5, P101 to P105, P201 to P205, P301 to P305,and P401 to P405) and the center BC1 of the first block region B1.

Specifically, since the P203 pixel region has the same center as thecenter BC1 of the first block region B1 (e.g., PC203=BC1), the microlens 220 of the P203 pixel region may not be shifted from the center ofthe P203 pixel.

Since the P103, P202, P204, and P303 pixel regions are adjacent to theP203 pixel region to share the side surface, the distance between thecenter BC1 of the first block region B1 and the center of each pixelregion (e.g., vertical centerline PC303 of the P303 pixel region) may bethe same as the first distance D1.

The micro lenses 220 of the P103, P202, P204, and P303 pixel regions maybe shifted in the direction of the P203 pixel region, that is, in thedirection of the center BC1 of the first block region B1 by a firstinterval S1.

In contrast, since the P102, P104, P302, and P304 pixel regions areadjacent to the pixel region of P203 in the diagonal direction, thedistance between the center BC1 of the first block region B1 and thecenter of each pixel region (e.g., vertical centerline PC302 of the P302pixel region) may be the same as the second distance D2. At this time,the second distance D2 may naturally be larger than the first distanceD1.

The micro lenses 220 of the P102, P104, P302, and P304 pixel regions maybe shifted (“laterally offset” from respective pixel region centerlines)in the direction of the P203 pixel region, that is, in the direction of(“towards”) the center BC1 of the first block region B1 by the secondinterval S2. At this time, the second interval S2 may be larger than thefirst interval S1.

Since the P3, P201, P205, and P403 pixel regions overlap the P203 pixelregion in the direction of row or column and are spaced apart (“isolatedfrom direct contact with”) the P203 pixel region by one pixel regiontherebetween, the distance between the center BC1 of the first blockregion B1 and the center of each pixel region (e.g., vertical centerlinePC3 of the P3 pixel region) may be the same as the third distance D3. Atthis time, the third distance D3 may be larger than the first distanceD1 and the second distance D2.

The micro lenses 220 of the P3, P201, P205, and P403 pixel regions maybe shifted in the direction of the P203 pixel region, that is, in thedirection of the center BC1 of the first block region B1 by a thirdinterval S3. At this time, the third interval S3 may be larger than thefirst interval S1 and the second interval S2.

Since the P1, P5, P401 and P405 pixel regions are spaced apart from(“isolated from direct contact with”) the pixel region of P203 in thediagonal direction by an interval of one pixel region therebetween, thedistance between the center BC1 of the first block region B1 and thecenter of each pixel region (e.g., vertical centerline PC5 of the P5pixel region) may be the same as a fourth distance D4. At this time, thefourth distance D4 may be larger than the first distance D1, the seconddistance D2, and the third distance D3.

The micro lenses 220 of the P1, P5, P401 and P405 pixel regions may beshifted by the fourth interval S4 in the direction of the P203 pixelregion, that is, in the direction of the center BC1 of the first blockregion B1. At this time, the fourth interval S4 may be larger than thefirst interval S1, the second interval S2, and the third interval S3.

In addition, since the distance between the P101, P105, P301, and P305pixel regions and the first block region B1 is larger than the thirddistance D3 and smaller than the fourth distance D4, the shiftedinterval of the micro lens 220 may be larger than the third interval S3and smaller than the fourth interval S4.

That is, as the distance between the center of the first block region B1and the center of each pixel region is larger, the shifted interval ofthe micro lens 220 may become large.

FIG. 9 is a plan view for explaining the image sensor including theblock region of FIG. 8 and further including a plurality of blockregions B1, B2, B3, B4, B101, B102, B103, B104, B201, B202, B203, B204,B301, B302, B303, and B304. Each block region shown in FIG. 9, which mayalso be referred to herein as a block region of substrate 100, may havea similar structure as the block region B1 shown in at least FIG. 8.Accordingly, a first image sensor 1220 that includes the pixel array1000 shown in at least FIG. 9 may including a plurality of block regionsB1 to B304, where each block region includes a plurality of pixelregions, for example the pixel regions P1 to P405 as shown in FIG. 8with regard to block region B1. As shown in at least FIG. 7, each pixelregion of the plurality of pixel regions of each block region mayinclude a separate photoelectric element 110 of a plurality ofphotoelectric elements 110 in the substrate 100. Restated, the pluralityof photoelectric elements 110 may be in separate, respective pixelregions. As further shown in at least FIG. 7, each pixel region of theplurality of pixel regions of each block region may include a separatemicro lens 220 of a plurality of micro lenses 220 on the substrate 100.Restated, the plurality of micro lenses 220 may be on separate,respective pixel regions. As shown above with reference to FIG. 8, eachmicro lens 220 of the plurality of micro lenses may be laterally offsetfrom a vertical centerline PC1 of the pixel region (e.g. P1) in whichthe micro lens 220 is included towards a center BC1 of the block region(e.g., B1). As shown in FIGS. 8-9, each block region of the plurality ofblock regions may include a common shifted shape of the plurality ofmicro lenses of the block region. For example, as shown in FIG. 8, themicro lenses 220 of block region B1 are each laterally offset from thevertical centerline of respective pixel regions (save for the micro lens220 of pixel region P203) such that the block region B1 has a particularpattern (“configuration”) of micro lenses 220. Such a pattern of microlenses 220 may be referred to herein as a “shifted shape” of the microlenses 220 of the block region B1. As further shown in FIG. 9, each ofthe block regions B1 to B304 may have a common “shifted shape” based oneach including the same (“a common”) pattern of micro lenses 220therein.

As shown in FIG. 9, at least two block regions (e.g., B1 and B2) of thefirst image sensor 1220 may include common quantities of pixel regions.As further shown, at least two block regions (e.g., B1 and B2) of thefirst image sensor 1220 may each include pixel regions aligned as acommon quantity of rows and a common quantity of columns.

As shown in FIGS. 8-9, the intervals (e.g., D1, D2, D3, D4, etc.)between micro lenses 220 of the pluralities of micro lenses in the blockregions may not be constant.

Referring to FIGS. 8 and 9, in the pixel array 1000 of the first imagesensor 1220 according to some example embodiments of the presentinventive concepts, the micro lens 220 may be shifted in units of blockregions. In this case, the shifted shape of the micro lens 220 of eachblock region may be the same.

For example, the micro lenses 220 of the first block region B1 may beshifted to the center of the first block region B1, and the micro lenses220 of the second block region B2 may be shifted to the center of thesecond block region B2. The shift shapes of these micro lenses 220(e.g., a shape of each separate pattern of micro lenses 220 in eachseparate block region) may be completely identical to each other (e.g.,may be a common shape). At this time, the expression “completelyidentical” is a concept including a fine step according to themanufacturing process.

FIG. 10 is a cross-sectional view taken along the line X-X′ of FIG. 9.

Referring to FIG. 10, in the first image sensor 1220 according to someexample embodiments of the present inventive concepts, the focusing to aparticular target may be improved by shifting the micro lens 220 inunits of block regions. Basically, one micro lens 220 may uniformly seeall sides on the basis of the original pixel region, and instead only asmall number of pixel regions may collect reflected beam for aparticular target.

In contrast, in the first image sensor 1220 according to some exampleembodiments of the present inventive concepts, as the micro lens 220 isshifted in units of block regions, the area of the beam collectionregion of the block region is partially reduced. Instead, within thebeam collection region of the block region, all the micro lenses 220 maysimultaneously collect the reflected beam of the same target.

Accordingly, for targets that are blurred and are imaged at lowresolution in a conventional image sensor, the first image sensor 1220according to some example embodiments of the present inventive conceptsmay image the target with clearer and higher resolution.

Referring to FIGS. 9 and 10, the boundary separation film 130 definingthe boundary of each pixel may define the boundary of the block regionat the boundary of each block region, such that a boundary separationfilm 130 at least partially defines adjacent block regions such that theboundary separation film 130 is divided between the adjacent blockregions. That is, the first boundary separation film (130, K1) betweenthe fifth pixel region P5 and the sixth pixel region P6 may define aboundary between the first block region B1 and the second block regionB2 such that the first boundary separation film (130, K1) at leastpartially defines the first block region B1 and the second block regionB2 such that the first boundary separation film (130, K1) is dividedbetween the first and second block regions B1 and B2. Similarly, thesecond boundary separation film (130, K2) between the tenth pixel regionP10 and the eleventh pixel region P11 may define the boundary betweenthe second block region B2 and the third block region B3 such that thesecond boundary separation film (130, K2) at least partially defines thesecond block region B2 and the third block region B3 such that thesecond boundary separation film (130, K2) is divided between the secondand third block regions B2 and B3.

Accordingly, the first boundary separation film (130, K1) may define theboundary between the first block region B1 and the second block regionB2, and the second boundary separation film (130, K2) may define theboundary between the second block region B2 and the third block regionB3.

The micro lens 220 of the first block region B1 and the micro lens 220of the second block region B2 may be disposed symmetrically on the basisof the first boundary separation film (130, K1). The micro lens 220 ofthe second block region B2 and the micro lens 220 of the third blockregion B3 may be disposed symmetrically on the basis of the secondboundary separation film (130, K2). This can be due to the fact that thearrangements of the micro lenses 220 of the first block region B1through the third block region B3 are identical to each other.

Restated, the plurality of micro lenses 220 located in the first blockregion B1 and the plurality of micro lenses 220 located in the secondblock region B2 may collectively include a symmetrical pattern of microlenses 220 with each other on a basis of the first boundary separationfilm (130, K1), and the plurality of micro lenses 220 located in thesecond block region B2 and the plurality of micro lenses 220 located inthe third block region B3 may collectively include a symmetrical patternof micro lenses 220 with each other on a basis of the second boundaryseparation film (130, K2).

As shown in FIGS. 9-10, each block region (e.g., block region B1) mayinclude micro lenses 220 that are laterally offset from separate,respective pixel region vertical centerlines (e.g., PC1 of the P1 pixelregion, PC5 of the P5 pixel region, etc.). As further shown, each blockregion (e.g., block region B1) may include at least one micro lens 220that is not laterally offset from (e.g., is aligned with) a pixel regionvertical centerline (e.g., PC3 of the P3 pixel region).

Hereinafter, the first image sensor 1220 according to some exampleembodiments of the present inventive concepts will be described withreference to FIGS. 1, 2, 6, and 11 to 13. The repeated parts of theabove-described embodiments will be simplified or omitted.

FIG. 11 is a cross-sectional view illustrating an image sensor accordingto some example embodiments of the present inventive concepts.

Referring to FIGS. 1, 2, 6, and 11, the first image sensor 1220according to some example embodiments of the present inventive conceptsmay include a metal shield layer 201, an opening 204, and a filling film211.

The metal shield layer 201 may be formed on the lower planarization film180. The metal shield layer 201 may cover a part of the lowerplanarization film 180 and may expose the remaining part. Therefore, theopening 204 may be defined.

The metal shield layer 201 may block the incident beam from going towardthe photoelectric element 110 in the substrate 100. That is, the metalshield layer 201 may block other portions except for the opening 204 sothat only the vertical component of the incident beam can reach thephotoelectric element 110. This is because, in order to clearlyrecognize small-size targets such as fingerprint ridges and valleys inthe object sensing such as fingerprint sensing, it is necessary to blocksurrounding beam that is not vertical.

The metal shield layer 201 may include a metal. The metal shield layer201 may include, for example, at least one of tungsten (W), aluminum(Al), and copper (Cu).

The upper planarization film 210 may be formed on the metal shield layer201. In some example embodiments of the present inventive concepts, acolor filter may be additionally formed between the upper planarizationfilm 210 and the metal shield layer 201.

The metal shield layer 201 may be seen like a plurality of structuresseparated from each other by the opening 204 in the cross section asshown in FIG. 11. However, the metal shield layer 201 may be connectedto each other in the planar structure. That is, since the opening 204may have a circular shape in a planar structure, the opening 204 may besurrounded by the metal shield layer 201.

The opening 204 is defined by the metal shield layer 201 and may beformed to be aligned at the center BC1 of the first block region B1. Theopening 204 may be aligned with the photoelectric element 110. That is,the photoelectric element 110 and the opening 204 may be aligned in thevertical direction to match the center BC1 of the first block region B1.Therefore, the vertical component of the incident beam may reach thephotoelectric element 110 in the substrate 100 through the opening 204.

The filling film 211 may fill the inside of the opening 204. The fillingfilm 211 is made of a transparent material and allows incident beam topass therethrough. The filling film 211 may include, for example, atleast one of a silicon oxide film-based substance, a silicon nitridefilm-based substance, a resin, or a combination thereof.

FIG. 12 is a conceptual perspective view for explaining a fingerprintsensing system including the image sensor of FIG. 11, and FIG. 13 is anexploded perspective view for explaining a fingerprint sensing systemincluding the image sensor of FIG. 11.

Referring to FIGS. 12 and 13, the fingerprint sensing system 10 mayinclude a display panel 1100 and a fingerprint sensor 1200. Thefingerprint sensor 1200 illustrated in FIG. 12 may be an opticalfingerprint sensor that recognizes the fingerprints by sensing beamreflected by the fingerprint ridges and valleys between the ridges viathe first image sensor 1220. According to some example embodiments, thefingerprint sensor 1200 may include a pinhole mask 1210 for allowing thebeam reflected by the fingerprint to pass, and a first image sensor 1220which senses the beam passing through the pinhole mask 1210 to generatean electrical signal. According to some example embodiments, the pinholemask 1210 may be formed of an opaque material so that beam is allowed topass through the pinhole (H), while blocking beam from passing through aregion in which the pinhole (H) is not formed. In some exampleembodiments, according to some example embodiments, the pinhole mask1210 may be formed of a material with low reflectivity.

Various kinds of display panels may be applied to the display panel1100. According to some example embodiments, the display panel 1100 maybe an OLED display panel which includes an OLED layer formed with anOLED (organic beam-emitting diode) which emits beam having one or aplurality of colors to perform a display operation. However, someexample embodiments of the present inventive concepts does not need tobe limited thereto, and the fingerprint sensing system 10 according tosome example embodiments of the present inventive concepts maycorrespond to various types of display panels such as an LCD displaypanel which performs the display operation, using a general backlight orthe OLED. Alternatively, in addition to the above-described OLED displaypanel and LCD display panel, even when the beam from the beam source ofthe display panel is reflected by the fingerprint and is transferred inthe direction of the back plane of the display panel (or in thedirection of the fingerprint sensor 1200), the display panel may also beapplied to the display panel 1100 according to some example embodimentsof the present inventive concepts.

On the other hand, the fingerprint sensor 1200 may be provided as asemiconductor chip or a semiconductor package and may be attached to oneside of the display panel 1100. According to some example embodiments,the first image sensor 1220 may be provided as a semiconductor layer ora semiconductor chip in which a plurality of photoelectric conversionelements (e.g., a photodiode, a phototransistor, a photogate and apinned photodiode) is formed. According to some example embodiments, thefirst image sensor 1220 may be a semiconductor layer on which an imagesensor such as a CIS (CMOS Image Sensor) or a CCD (Charge CoupledDevice) is provided. In the following description, it is assumed thatthe photoelectric conversion element in the first image sensor 1220 isprovided as a photodiode.

According to some example embodiments, in providing the fingerprintsensor 1200, the pinhole mask 1210 may be stacked on the first imagesensor 1220 in the course of packaging of the first image sensor 1220.Alternatively, in a process for providing the first image sensor 1220,the pinhole mask 1210 may be stacked on the first image sensor 1220 inthe form of a layer in one or more layers constituting the first imagesensor 1220. That is, the fingerprint sensor 1200 may be provided in theform in which the pinhole mask 1210 is equipped in the first imagesensor 1220, and the packaging process can be performed on the firstimage sensor 1220 equipped with the pinhole mask 1210. That is,according to some example embodiments, the pinhole mask 1210 and thefirst image sensor 1220 may be formed integrally.

The pinhole mask 1210 may be provided in various ways, using a materialwith low beam transmittance and low reflectance. For example, thepinhole mask 1210 may be provided, using a material which hascharacteristics of low reflectance (or high absorptivity), whileblocking beam, and in which its hardness may be maintained for changesin temperature or humidity. As an example, the pinhole mask 1210 may beprovided by applying a TiN (titanium nitride) substance onto a siliconmaterial and then forming the pinhole (H). Alternatively, substancessuch as black nickel and anodized aluminum as different substances otherthan silicon may be used as materials of the pinhole mask 1210.

According to some example embodiments, the OLED layer and the pinholemask 1210 provided in the OLED display panel may be disposedsubstantially in parallel (e.g., in parallel within manufacturingtolerances and/or material tolerances). Thus, the beam from theplurality of OLEDs in the OLED layer can to be transferred in thedirection of the fingerprint located on the cover glass, and the beamreflected by the fingerprint can be transferred to the pinhole mask 1210within an angle of view formed by the pinhole (H) in the pinhole mask1210. Thus, in the fingerprint sensor according to some exampleembodiments of the present inventive concepts, it is not necessary toprovide another beam guide means for controlling the path through whichbeam is transferred for sensing the fingerprint.

The fingerprint sensor 1200 sense the fingerprint which is in contactwith or located near the display panel 1100. In the fingerprint sensingsystem 10 according to the embodiments of the present inventiveconcepts, a fingerprint being in contact with the display of a wearabledevice such as a smartphone can be recognized, without the necessity ofmounting a separate button for fingerprint recognition. For example,when the display panel 1100 corresponds to the OLED display panel andthe user's fingerprint is placed on the cover glass of the display panel1100, beam from the OLED layer in the display panel is used as a beamsource and transferred and reflected to the user's fingerprint, and thereflected beam passes through the panel backplane and may be transferredto the first image sensor 1220 through the pinhole mask 1210.

The first image sensor 1220 includes a plurality of pixel regions, andeach pixel region senses beam reflected by different regions of thefingerprint and generates an electrical signal corresponding to thesensed beam. Each pixel region (e.g., at least one photoelectric elementincluded therein) may generate an electrical signal corresponding to thebeam reflected to the ridge of the fingerprint or may generate anelectrical signal corresponding to the beam reflected to the valleybetween the ridges. The signal may be communicated to a control circuit,including control circuit 2000. The amount of beam detected by thephotoelectric elements (e.g., photodiodes) may vary depending on theshape of the fingerprints from which the beam is reflected, andelectrical signals having different levels may be generated depending onthe amount of sensed beam. That is, the electrical signals from theplurality of pixel regions may include contrast information (or imageinformation), respectively, and it is possible to determine whether theregion corresponding to each pixel region is the ridge or the valley,and by combining the determined information, an overall fingerprintimage may be constructed.

The regions of the fingerprint optically sampled in the fingerprintsensing system 10 may be defined. As an example, a plurality offingerprint pixels (WFP) may be defined to correspond to the pluralityof pixel regions of the first image sensor 1220, and each fingerprintpixel (WFP) may be correspond to an object region indicated by onepinhole (H) and one pixel region. As various factors, the shape and sizeof the fingerprint pixel (WFP) corresponding to each pinhole (H) may bedetermined in accordance with the distance between the display panel1100 and the pinhole mask 1210, the distance between the pinhole mask1210 and the first image sensor 1220, the thickness (T) of the pinholemask 1210, the diameter (d) and the shape of the pinhole (H) or thelike.

Each of the fingerprint pixels (WFP) may correspond to one pinhole (H)in the pinhole mask 1210. A region which reflects the beam capable ofpassing through one pinhole (H) may be included in each fingerprintpixel (WFP), and the region may be defined as an optical samplingregion. Depending on the optical sampling region, the optical sensingregion corresponding thereto may also be defined in the first imagesensor 1220. As an example, the optical sensing region may include apixel region.

On the other hand, although FIG. 13 illustrates a configuration in whichthe fingerprint pixel (W_(FP)) is located in the entire region of thedisplay panel 1100, some example embodiments of the present inventiveconcepts does not need to be limited thereto. As an example, thefingerprint pixel (W_(FP)) may be located only in a partial region ofthe display panel 1100. Accordingly, when a user's fingerprint islocated in a specific region of the display panel 1100, the fingerprintmay be sensed.

In some example embodiments, each of the plurality of pinholes (H) inthe pinhole mask 1210 may correspond to each of a plurality of pixelregions in the first image sensor 1220. For example, one pixel regioncorresponding to one pinhole (H) may include a single photodiode 11.Alternatively, one pixel region corresponding to one pinhole (H) mayinclude two or more photodiodes 11. FIG. 1 illustrates an example inwhich one pixel region includes a plurality of photodiodes 11 and thepixel region in the optical sensing region includes a plurality ofphotodiodes 11. That is, a plurality of pinholes (H) of the pinhole mask1210 is formed so as to be mapped to the plurality of pixels of thefirst image sensor 1220, the beam reflected by the fingerprint pixels inthe optical sampling region is sensed by one or more photodiodes in thepixel region, and the entire image of the fingerprint may bereconstructed by processing the electrical signals from the plurality ofpixel regions.

According to some example embodiments, a region within the first imagesensor 1220 may be defined to correspond to each of the fingerprintpixels (W_(FP)), and the region corresponding to each of the fingerprintpixels (W_(FP)) may include a plurality of photodiodes. In some exampleembodiments, the pixel region may correspond to a region including atleast a part of the plurality of photodiodes corresponding to thefingerprint pixel (W_(FP)). That is, one pixel region needs to sensebeam corresponding to the fingerprint pixel (W_(FP)) correspondingthereto, and it is necessary to prevent overlap of the beamcorresponding to another fingerprint pixel (W_(FP)). In the example ofFIG. 1, an example is illustrated in which the region corresponding toeach fingerprint pixel (W_(FP)) includes 5*5 photodiodes and the pixelregion includes 3*3 photodiodes as a part thereof. A fingerprint image(or a partial fingerprint image) may be constructed on the basis of theelectrical signals from 3*3 photodiodes in the region corresponding toeach fingerprint pixel (W_(FP)).

On the other hand, in some example embodiments, the fingerprint sensingsystem 10 has been described to sense the fingerprint of the user, butsome example embodiments of the present inventive concepts do not needto be limited thereto. For example, when a particular (or,alternatively, predetermined) object is positioned on the display panel1100, the fingerprint sensor 1200 senses the beam reflected by theparticular (or, alternatively, predetermined) object and may generatethe sensing result. When each fingerprint pixel of the fingerprintsensor 1200 generates image data as a sensing result, the image of theobject located on the display panel 1100 may be reconstructed, using theimage data from each fingerprint pixel of the fingerprint sensor 1200.

In the first image sensor 1220 according to some example embodiments, noadditional optical lens is required on the micro lens in order to sensethe fingerprint. Therefore, it may be important to sense the positionsof the ridge and the valley of the fingerprint with clear and highresolution, without considering a chief ray angle (CRA) of the opticallens.

As a result, the shift of the micro lens 220 of the first image sensor1220 is executed in units of block regions, and the positions of ridgesand valleys disposed in the fingerprint can be more clearly imaged.

Hereinafter, a second image sensor 1221 according to some exampleembodiments of the present inventive concepts will be described withreference to FIGS. 1 and 14 to 16. The repeated parts of theabove-described embodiments will be simplified or omitted.

FIG. 14 is a block diagram for explaining an image sensor according tosome example embodiments of the present inventive concepts, and FIG. 15is a conceptual diagram for explaining an image sensor according to someexample embodiments of the present inventive concepts. FIG. 16 is aconceptual diagram for explaining a binning mode of the image sensoraccording to some example embodiments of the present inventive concepts.

Referring to FIGS. 1 and 14, a control circuit 2000 of a second imagesensor 1221 according to some example embodiments of the presentinventive concepts may selectively execute a full mode and a binningmode (e.g., may selectively execute the full mode or the binning mode).The control circuit 2000 of the second image sensor 1221 may furtherinclude a selection circuit 2400.

Referring to FIGS. 14 and 15, a row driver 2300 and a selection circuit2400 of the control circuit 2000 may execute imaging, using informationof all the pixel regions of the pixel array 1000 in the full mode.

The pixel array 1000 may include an RGB pixel region of a bayer pattern.That is, the blue pixel (B), the red pixel (R), and the green pixel (Gb,Gr) may be disposed within the pixel array 1000 in the bayer pattern.Restated, the pixel array 1000 may include block regions that includeseparate color regions (e.g., first to third color regions) which areconfigured to receive beams of different colors. For example, the bluepixel (B) may be a blue color region that is configured to receive beamsof a blue color, the red pixel (R) may be a red color region that isconfigured to receive beams of a red color, and the green pixel (Gb, Gr)may be a green color region that is configured to receive beams of agreen color.

The blue pixel (B) is a pixel region that filters the remaining partexcept for the blue color component of the incident beam, using a bluecolor filter as the color filer, and the red pixel (R) is a pixel regionthat filters the remaining part except for the red color component ofthe incident beam, using a red color filter as the color filter. Thegreen pixel (Gb, Gr) is a pixel region which filters the remaining partexcept for the green color component of incident beam, using a greencolor filter as the color filter.

All the pixel regions adjacent to the blue pixel (B) of the pixel array1000 according to the bayer pattern are the green pixels (Gb, Gr), andall the pixel regions adjacent to the red pixel (R) may be green pixels(Gb, Gr). Further, the blue pixel (B) and the red pixel (R) may beadjacent to each other in an oblique direction.

The control circuit 2000, in selectively executing the full mode, mayutilize the information (e.g., electrical signals) of all the pixelregions of the pixel array 1000 in the full mode. That is, the rowdriver 2300 may apply a signal to all the row signal lines (R1 to R7).Further, the selection circuit 2400 may receive the outputs of all thecolumns via the column signal lines (C1 to C7).

After receiving the output of the pixel array 1000, the selectioncircuit 2400 may transmit the output to the correlated double sampler2500.

Referring to FIGS. 14 and 16, the row driver 2300 and the selectioncircuit 2400 of the control circuit 2000 may execute the imaging, usingonly information of a partial pixel region of the pixel array 1000 inthe binning mode. Restated, the control circuit 2000, in selectivelyexecuting the binning mode, may utilize a limited portion of theinformation (e.g., electrical signals) of the pixel regions (e.g., theinformation of a limited portion of the pixel regions) of the pixelarray 1000.

For example, only the outputs of P1, P3, P201 and P203 pixel regions areused in the first block region B1, and the entire first block region B1may be used as the blue pixel (B). Similarly, only the outputs of theP4, P6, P204 and P206 pixel regions are used in the second block regionB2, and the entire second block region B2 may be used as the green pixel(Gb). In the fifth block region (B5), only the outputs of the pixelregions P304, P306, P504, and P506 are used, and the entire fifth blockregion B5 may be used as the red pixel (R). For example, the controlcircuit 2000 may selectively execute the binning mode such that eachblock region of the pixel array 1000 utilizes only one color region(e.g., only one or more blue pixels (B) included therein) of multiplecolor regions included therein.

The binning mode may reduce the amount of transfer data to dramaticallyimprove the operation speed of the image sensor. However, the resolutionmay be relatively lowered during the binning mode. In order to preventthis, the second image sensor 1221 of some example embodiments mayperform the shift of the micro lens 220 in the same unit as the blockregion unit in which the binning mode is executed.

Through this, the second image sensor 1221 according to some exampleembodiments is capable of performing the imaging without lowering theresolution, while having the advantage of high-speed transfer of thebinning mode.

In concluding the detailed description, those skilled in the art willappreciate that many variations and modifications can be made to thepreferred embodiments without substantially departing from theprinciples of the present inventive concepts. Therefore, the disclosedpreferred embodiments of the inventive concepts are used in a genericand descriptive sense only and not for purposes of limitation.

What is claimed is:
 1. An image sensor, comprising: a substrate whichincludes a plurality of block regions, each of the block regionsincluding a first to fifth pixel regions, the second and third pixelregions arranged in a first direction with the first pixel regioninterposed therebetween, and the fourth and fifth pixel regions arrangedin a second direction with the first pixel region interposedtherebetween, and the second direction intersecting the first direction;first to fifth photoelectric elements in separate, respective pixelregions of the first to fifth pixel regions; and first to fifth microlenses on separate, respective pixel regions of the first to fifth pixelregions, wherein the first micro lens has a same vertical centerline asa vertical centerline of the first pixel region, the second micro lensis laterally offset from a vertical centerline of the second pixelregion by a first interval, the third micro lens is laterally offsetfrom a vertical centerline of the third pixel region by the firstinterval, the fourth micro lens is laterally offset from a verticalcenterline of the fourth pixel region by a second interval, and thefifth micro lens is laterally offset from a vertical centerline of thefifth pixel region by the second interval.
 2. The image sensor of claim1, wherein each of the block regions includes a common pattern of thefirst to fifth micro lenses, such that each of the block regionsincludes a common shifted shape of the first to fifth micro lenses. 3.The image sensor of claim 1, wherein a center of the first pixel regionis the same with a center of each of the block regions.
 4. The imagesensor of claim 1, wherein distances between the vertical centerline ofthe first pixel region and the vertical centerline of each of the secondto fourth pixel regions are the same each other.
 5. The image sensor ofclaim 1, wherein the first interval and the second interval are the sameeach other.
 6. The image sensor of claim 1, wherein the first to fifthmicro lenses are laterally offset towards the vertical centerline of thefirst pixel region.
 7. The image sensor of claim 1, wherein each of theblock regions further includes a sixth pixel region spaced apart fromthe first pixel region in the first direction with the second pixelregion interposed therebetween, wherein the sixth pixel region includesa sixth photoelectric elements and a sixth micro lens, and the sixthmicro lens is laterally offset from a vertical centerline of the sixthpixel region by a third interval greater than the first interval.
 8. Theimage sensor of claim 1, further comprising: a boundary separationtrench in the substrate, the first pixel region being defined to beseparated from the second to fourth pixel regions by the boundaryseparation trench; and a reflection prevention film at least partiallyfilling the boundary separation trench.
 9. The image sensor of claim 8,further comprising: a lower planarization film on the reflectionprevention film and the substrate; and a side surface reflectionprevention film on the lower planarization film and covering a part ofthe lower planarization film, the side surface reflection preventionfilm overlapping the boundary separation trench in a vertical direction.10. The image sensor of claim 1, further comprising a metal shield layerincluding an opening exposing a part of the substrate, between thesubstrate and the first micro lens, wherein the opening of the metalshield layer has a circular shape in a plan view.
 11. The image sensorof claim 1, further comprising a control circuit configured to receiveelectrical signals generated by the first to fifth photoelectricelements.
 12. The image sensor of claim 11, wherein the electricalsignals include image data of fingerprints.
 13. An image sensor,comprising: a substrate which includes a plurality of block regions,each of the block regions including a center pixel region and aplurality of first peripheral pixel regions disposed around the centerpixel region; a first photoelectric element in the center pixel region;a first micro lens on the center pixel region; a second photoelectricelement in each of the first peripheral pixel regions; and a secondmicro lens on each of the first peripheral pixel regions, wherein acenter of the second micro lens is shifted from a vertical centerline ofeach of the first peripheral pixel regions towards a center of the firstmicro lens.
 14. The image sensor of claim 13, wherein each of the blockregions includes a common pattern of the first and second micro lenses,such that each of the block regions includes a common shifted shape ofthe first and second micro lenses.
 15. The image sensor of claim 13,wherein a center of the center pixel region is the same with a center ofeach of the block regions.
 16. The image sensor of claim 13, whereineach of the block regions has a square shape, and the center pixelregion and the first peripheral pixel regions are arranged in a form of(N×N) matrix (here, N is a natural number more than 3).
 17. The imagesensor of claim 13, wherein each of the block regions has a rectangleshape, and the center pixel region and the first peripheral pixelregions are arranged in a form of (N×M) matrix (here, N and M arenatural numbers more than 3, and M is different from N).
 18. The imagesensor of claim 13, wherein each of the block regions further includes aplurality of second peripheral pixel regions disposed around the firstperipheral pixel regions, each of the second peripheral pixel regionsincludes a third photoelectric element and a third micro lens, and acenter of the third micro lens is shifted from a vertical centerline ofeach of the second peripheral pixel regions towards the center of thefirst micro lens.
 19. The image sensor of claim 18, wherein the centerof the second micro lens is shifted from the vertical centerline of eachof the first peripheral pixel regions by a first interval, and thecenter of the third micro lens is shifted from the vertical centerlineof each of the second peripheral pixel regions by a second intervalgreater than the first interval.
 20. The image sensor of claim 13,wherein the image sensor is a fingerprint sensor that recognizesfingerprints by sensing beam reflected by fingerprint ridges andfingerprint valleys between the fingerprint ridges.